Methylamine → 2-(Dimethoxymethyl)-5,6,7,8-tetrahydro-n-methyl-1,8-naphthyridine-3-methanamine

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Reaction Steps

Methylamine (7.5 ml, 15.00 mmol) was added to a solution of 2-(dimethoxymethyl)-5,6,7,8-tetrahydro-1,8-naphthyridine-3-carbaldehyde (intermediate 41, 3 g, 12.70 mmol) in MeOH (60 ml) and the reaction mixture was stirred at room temperature for approximately 3 h. NaBH4 (690 mg, 18.24 mmol) was added portonwise and stirring was continued at room temperature for 40 min. Solvents were concentrated and the residue was partitioned between DCM and water. The aqueous layer was extracted with DCM and the organic layers were washed with water. The combined organic layers were dried using Na2SO4, filtered and evaporated to yield the title compound as an orange oil. (UPLC-MS 3) tR 0.35 min; ESI-MS 252.2 [M+H]+. 1H NMR (600 MHz, CDCl3) δ 7.29 (s, 1H), 5.30 (s, 1H), 4.91 (br s, 1H), 3.73 (s, 2H), 3.36-3.47 (m, 8H), 2.73 (t, 2H), 2.47 (s, 3H), 2.21 (br s, 1H), 1.95-1.87 (m, 2H).

Provenance & Evidence